This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Introduction: Morphologic brain differences have been identified between children with autism and typically-developing children, though findings have been inconsistent across studies. One potential cause is the variability in brain morphology resulting from the influence of multiple genetic and environmental factors on brain development. A strategy to control for such factors is to compare brain structure between siblings discordant for autism. Specific Aim: To assess the relationship between brain morphology and autism using voxel-based morphometry to examine siblings discordant for autism. Methods: To read about other projects ongoing at the Lucas Center, please visit http://rsl.stanford.edu/ (Lucas Annual Report and ISMRM 2011 Abstracts)